Let’s start with some definitions because there are many terms that are still used, but have technically been retired from the medical literature. “Drowning” was initially describing death from immersion or submersion with asphyxia or respiratory impairment, while other terms such as "wet drowning,” "dry drowning,” "active or passive drowning,” "near-drowning,” "secondary drowning,” "silent drowning," and many others were various forms of non-fatal immersion/submersion injury.
The new definition states that “drowning is a process resulting in primary respiratory impairment from submersion in a liquid medium. Implicit in this definition is that a liquid-air interface is present at the entrance to the victim's airway, which prevents the individual from breathing oxygen.”This means that drowning can really just be broken down into two main forms, fatal drowning and non-fatal drowning; which is a drowning event in which the process of respiratory impairment is stopped before death, and the victim survives.
The World Health Organization classifies non-fatal drowning based on the severity of respiratory symptoms immediately after the drowning process has been stopped:
- Mild impairment: Breathing, involuntary distressed coughing and fully alert
- Moderate impairment: Difficulty breathing and/or disoriented but conscious
- Severe impairment: Not breathing and/or unconscious
We’ll get into some of the nuance in a bit, but it’s just important to note that the word drowning no longer implies death.
The circumstances in which drowning can occur vary by the victim’s age. Children, particularly in the US, are more likely to drown in a pool, whereas adults are more likely to drown in lakes, rivers, and oceans. More than half of adult drownings involve alcohol (no, not drowning in a G&T).
In Florida recently, rip currents were responsible for 8 deaths in four days. I can tell you from personal experience that rip currents are scary as hell, but that’s another story for another time.
Other than alcohol and rip currents, other things that can lead to drownings are trauma, a medical event such as cardiac arrest or seizure, or just inability to swim, or swimming alone.
Regardless of what may have caused the event, a drowning victim may initially be thrashing around, as there is an early period of panic.That panic, and exertion, will increase the body's oxygen needs.
The flailing might cause accidental water in the lungs while gasping, or person may try to hold his/her breath, but eventually carbon dioxide in the blood will trigger a reflex to breathe, and that's how a significant amount of water will end up in the lungs.
When fluid enters the lungs, it impairs the alveoli, air sacks in the lungs where gas exchange occurs (oxygen from the lungs migrates into the blood, carbon dioxide leaves the blood and is exhaled). The damage from water in the lungs can happen with as little as a mouthful.*
Next there's hypoxia, loss of consciousness, respiratory efforts stop, and cardiopulmonary arrest is the final phase.
The lack of oxygen in the body will affect every organ, but first and foremost the heart and brain. If a person does survive a drowning event, long term neurologic disabilities may be present in up to 20%.
Anyway, symptoms in non-fatal drowning can be as mild as a slight cough or slight trouble breathing, and these people still need a good evaluation by a medical professional. Other symptoms that are obviously more profound, in addition to real respiratory distress, include vomiting, wheezing, confusion, and of course unresponsiveness. While at a cellular level, the lack of oxygen wreaks havoc in all of the organs.
Treatment is simply giving the body what it needs, oxygen.Getting that oxygen IN is where it can get complicated.
Paramedics and emergency departments will have plenty of options, from just giving supplemental oxygen through a mask up to inserting a tube into the lungs and putting the drowning victim on a ventilator.
What can you do without a ventilator?
First, activate 911 and get the person out of the water--as long as it is safe for you to do so. A friend of mine died while trying to save his son from drowning. It's truly tragic.
Next, you'd follow the steps in CPR, but not the new CPR that prioritizes early compressions, but old school CPR that promoted ABC, airway, breathing, circulation.
If a person is unresponsive, get them to a firm surface and deliver two to five rescue breaths, and follow with 30 chest compressions.
Current CPR focuses on chest compressions for non-drowning cardiac arrest, but with drowning, getting oxygen into the lungs is vital. Continue to cycle through 2 breaths and 30 compressions until help arrives, or the rescue efforts seem futile.
One note of caution, involuntary vomiting is even more likely in these types of resuscitative efforts, so be warned, and use a barrier device if available,The bottom line is that even non-fatal drowning can have long term consequences, so prevention is key. Don't swim if intoxicated, heed warnings about rip tides, don't dive into water if it's shallow or has obstacles, use your PFD if you're on a canoe/kayak/SUP, and always keep your water wings on.
*So, the alveolar damage happens with about 1-3mL/kg of liquid. To save you from doing the math, that’s between 70mL and 210mlL of fluid for a person weighing about 150lbs. That 70mL translates into about 2.5 fluid ounces. I tried to find exactly, or approximately, how much “a mouthful” was, but I couldn’t find a good source. I conducted my own experiment… I took a ½ cup measuring container (4 fl oz) and almost got all of the water in my mouth… so I estimate that at about 2.5 ounces, which is about 70mL. which I then corroborated by taking a 60cc syringe I had, filled it with water and then filled my mouth, had some room to spare... #science
Please remember, the information presented here, including but not limited to, text, graphics, images and other material contained on this website are for informational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis or treatment.
Comments
Post a Comment